Edge non-uniformity of metal deposition or etch on substrates has been found in many products especially in plasma processing environments. The edge non-uniformity may be film thickness and property non-uniformity, and may be edge-to-edge non-uniformity or center-to-edge non-uniformity.
In many deposition chambers, both atomic layer deposition and chemical vapor deposition, rotating pedestal/heaters are used to improve/reduce non-uniformity. In most cases, non-uniformity comes from non-uniform chemical delivery, flow distribution, chamber features, and temperature non-uniformity from the chamber body and surrounding components. Using a rotating pedestal can distribute the local effect of these variations and improve the non-uniformity.
However, the inventors have found that undesirable edge non-uniformity still exists in many cases. Therefore, there is a need in the art for apparatus and methods to reduce edge-to-edge and center-to-edge non-uniformity during metal deposition or etch processes on substrates.